Variable speed control device



Aug. 31, 1954 s. RENAUD 2,687,650 VARIABLE SPEED CONTROL DEVICE FiledApril 25, 1951 3 Sheets-Sheet l INVENTOR. AMUEL PA/AUD A r TOP/VFYS Aug.31, 1954 s. RENAUD 2,687,650 VARIABLE SPEED CONTROL DEVIgCE Fild April25 1951 3 Sheets-Sheet 2 INVENTOR. fiAML/[L PEA/A up Aug. 31, 1954 FiledA ril 23, 1951 S. RENAUD 2,687,650 VARIABLE SPEED CONTROL DEVICE 3Sheets-Sheet 5 INVENTOR. 5AMUE RENAUD Patented Aug. 31, 1954 UNITED sPATENT OFFICE VARIABLE SPEED CONTROL DEVICE Samuel Renaud, Dijon,Terrot, D

blissements Claims.

transmission system provided with V-belts and,

=anintermediate or jack shaft.

The object of the invention changes progressively, by infiniteincrements,

shifted or adjusted positions of the expandable pulleys.

For this purpose, the progressive change in speed according to the.

ing conjointly on their axis of rotation.

-According-to another feature of the invention,

of beinglmoved alonga planar path.

According to. another feature of the inventiongthe axis of rotation ofthe pulleys is re- 'straine'd and'guided in such a manner as tobeFrance, assignor to Etaijon, France, acompany '-Applicati0n April 23,1951; Serial No. 222,412

2 capable of being moved path.

along a part-cylindrical According to another feature of the invention,the external cheeks are mounted directly on a hub capable of slightaxial movement under. the

spending pulley.

According to another feature of the compensating means are formed byinvention,

agrammatically in the following accompanying drawings, wherein:

Fig. 1 is a diagrammatic View in planof a change speed device accordingto the invention shown in one of the extreme positions.

Fig. 2 is a view similar to that of Fig. 1, corresponding'with the otherextreme position. device in the position of Fig. 1, the tions accordingtoFig. 2 being lines.

Fig. 4 is an axial section to alarger scale, of the same device, with anactuating member capable of moving the axis of the'device in the sameplane.

Fig. 5 is a view in side elevation of the form of Figure 4.

extreme posishown in broken 'drical surface, and

two coaxial pulleys 3 and 4 each of changeable diameter turning aboutaninterme- I the displacement of the diate or jack-shaft axis 5 which isshiftable relative to the axis 2, through an infinite number of parallelpositions within its range of shifting, and driven by a belt 6, and apulley I of unchangeable diameter turning about an axis 8 which also maybe considered as fixed, and driven by a belt 9 passing around the pulley4.

Each intermediate or expandible pulley is formed by two cheeks lfl, I2,and H, I3. The internal cheeks l and H are formed integral with eachother, through the medium of a sleeve I l. The external cheeks l2, [3are formed with individual sleeves l so that they may shift slightlyaxially, the one relative to the other, but are clutched together at 25for conjoint rotation. Also, the internal and the external cheeks areheld together at 26 for rotation of all conjointly, notwithstandingaxial shifting of internal cheeks 10, H and their sleeve l4 relative toexternal cheeks l2, l3, and of the cheeks l2, I3 relative to oneanother.

In the extreme position of Fig. 1, which corresponds with the low speed,the cheeks l0, l2 of the pulley 3 are approached as close as possible,so that this pulley has the diameter of maximum winding. At the sametime the cheeks H, H of the pulley 4 are spaced apart as far aspossible, and as a result the pulley 4 has a diameter of minimumwinding. The pulleys 3 and 4 are thus seen to be mutually and oppositelychangeable in diameter.

When the axis 5 is moved parallel to itself, in such a manner as to moveit as far as possible away from the axis 2, whilst the pulleys I and 3,4 and 1 remain, same planes, so as to arrive at 511 (Figs. 2 and 3), itwill be appreciated that the tension of the driving belt 8 increasesbecause the distance between the axes 2 and Sincreases, whilst that ofthe driven belt 9 decreases, because the spacing of the axes 5 and 8decreases. It then results that, as the sleeve l4 slides freely in anaxial direction, the belt 6 applies to the cheeks l0, [2 a thrust whichwithdraws the cheek it from the cheek [2 by causing the sleeve [4 toslide towards the right, in the figure. Thus the reduction in thewinding diameter of the belt 6 on the pulleys 3 annuls the increase intension of this belt. As another consequence of the said sliding, thecheek ll approaches the cheek i3, whilst increasing the winding diameterof the pulley 4, and the increase of the winding diameter of this pulleyannuls the reduction in tension of the belt 9. This does not, for alldesigns, insure that the belt tensions will remain equal in alldisplaced positions of the axis 5; they will ordinarily remain equalonly if the design incorporates compensating means to expand or contractone of the pulleys 3, 4 automatically or manually in accordance with thetendency of a particular design to increase or to decrease the beltstension by a given displacement of axis 5. Compensatory means to thisend constitutes one of the important features of this invention.

It will be seen that the intermediate axis 5 may be moved, by means of asuitable member, in such a manner as to remain in the same plane, oralternatively, to describe a part-cylindrical surface, or even any othersurface. Further, it will be understood that the increase of thedistance between the two axes 5 and 2 does not correspond, in somecases, with the reduction in distance between the axes 5 and 8, andthat, for this reason,

intermediate axis 5 cannot alone exactly compensate for the change inbelt tension. In order to remedy this, the relative position of the axes2, 5 and 8 and the winding diameter of one pulley, independently of thatcaused by displacement of axis 5, is determined in such a manner as toensure a constant tension of the belts during the movement from 5 to 5a.However, in the case in which one of the axes, 8 for example, is notfixed actually, but is movable (case of rear suspension), a driven orautomatic compensating device modifies the winding diameter of one ofthe belts in such a manner as to reestablish the correct tension of thebelts.

In the form of construction shown in Figs. 4 and 5, relating to the caseof a change speed device provided with a control member moving the axisof the pulleys along a plane, it has been assumed that the whole of thedevice is supported by a chassis It.

The chassis is provided with two longitudinal or straight-line guides I!in which slide, toward opposite sides from the middle of the guide, theaxial supports N3 of a hub I9 of which one end is provided with a colletHi. The supports l8 have two plane faces contacting respectively theupper and lower faces of each guide, so that they are capable of beingmoved in this guide without being able to turn.

On the end of the hub opposite the collet 20 is mounted a sleeve 2|,provided with an arm 22, which has, for example, an elongated opening 23into which penetrates a pin 24 fixed to the chassis H5. The sleeve Eland the collet 20 serve in particular as stops for two ball bearings 39enabling the pulleys to turn on the hub and absorb the reactions due tothe belts.

Between the two stops thus formed and on the ball bearings 39 rest theexternal cheeks l2, l3 of the pulleys 3, 4, each cheek being extended bya tubular part l5 provided with a coupling dog clutch 25, the two dogsangularly engaging the external cheeks, whilst enabling the spacingbetween these to be varied. By such means the cheeks l2 and [3 are notactually joined against relative axial movement, but are joined toprevent relativ rotational movement.

On the tubular parts l5 slides, for example, a sleeve l4 supporting theinternal cheeks I0, H of the pulleys 3 and 4 and joining these checksH), l l for conjoint axial and rotational movement, only, whilstprohibiting movement of one relative to the other. Finally, a pin 26secured to the cheek H is engaged within a bore 21 passing through thecheek 13 in such a manner that while the external cheeks l2, l3 and theinternal be moved axially relatively to one another, they must allrotate together. Paired cheeks are wedged angularly, the cheeks Ii], 12and II, l3 forming respectively the intermediate pulleys 3 and 4 one ofwhich may be driven and the other of which will control and effect therotation of other members.

The sleeve M carrying the internal cheeks is moved on tubular parts l5as a result of the shifting of a control member preferably formed bylevers 28, hinged at 29 to the chassis l6 and provided with openings 30,in which the axial supports N3 of the hub may move. To a lever 28 issecured at 3| a rod 32, in such a manner that when a force is appliedthereto, in the direction of the arrow for example, the supports l8,being guided at H, are moved perpendicularly to the plane of Fig. 4:.When the driving pulley l is aligned with the left-hand pulley 3 and thepulley 4 at the right is aligned with the driven pulley 1, the sleeve I4is moved automatically towards the 2 *6875660 ltlghtofFigfl l, underthe"action'of-the tension whatrblaim isz "of'the belt;diacreasingthewindingdiameterof *lmA-variable speed control'deviceforuse'with the pulley 3 and increasing that of the pu11ey 4, drivin ndd v n'p ll y r n imbelted inthe'mar'merl already desoribedg "relationthroug'h the medium of I v belts lcon- The movement of the axis of thedevice may 5 netting each such pulley wlth lts r spe tive n vary thetension of one of the belts, as above de- 02? two expandable pulleys,said device comprisfamllicallyhirected'slot*33 provided in the'sleeve"initial 'positi'on' twoseparate pulley-rcheeks axf'duc es rotation ofthesleeve 2! aboutthe aiiisof I5 cheeks,-' each of the connected cheeks.rin rposicrowdstothe right the si eevelfiof the check it, and forshifting axially therealong relativexto and the enthesleevellywithrespect to the sleeve said separate cheeks, ionexoansion and con- !Thecam; 33' is so determined or designed that several cheeks for, conjointirotationzin lall exp ti n as h ax l pp r s i f he panded orcontractedpositlonsimeans to effect Y I9 move in the guide 11, the compensation ofthe 2 tension of the belts isene'cted al'ltoma'tifially. its. guidedpath, tgLincrease 1 tensjonxjn the one It willbe understood that, thiscompensation V-beIt and conversely to slaokenitensiondn' the rronepulley and rc'ons'equent contraction of! the xThe: axis of thepulleyswmayalso be moved pmother, means'reactingrbetween the hubean'done allel to itself otherwise than along a plane, that .wofisaid-iseparat .cheeks 130leffectaaxiallapprgach 1s, by describin for example apart-cylindrical or recession of the said separate cheeks relative fo me thepleferled 011e- 5 connected cheeks, and means to energize said Inthe e F u 6 and the member-5 form approach-effecting means, to effect acompensating the pulleys 3 a d 4 are the Same as in the ing axial shiftof the separate cheeks relative to preceding casee HOWBVBI, the huh ismade one another, and to maintain substantially coneccentric relativ yto a mounting Spindle stant the tensions in the two V-belts in thesevmounted rotata ly in the Chassis and is eral displaced positions ofthe hub, the approachvided with an arm 3 to Which is Secured D-efiecting means and its energizing means includerating arm 3 y app y apull t h rfld, ing a lever extendin between the hub and a diseffect ofwhich is to Obtain, s in the preceding between the hub and said lever,inclined helically casing, the move f the Sleeve h the of the hub toshift the hub axially during and as corresponding modifications 0f theWlndlng of a result of its displacement and the restraint of theintermediate pulleys 3 and 4.

The Comp meniber 15 here formed against one of said separate cheeks, andthe hub Sentially y a helically dlrected member takmg 5O bearingoppositely endwise against the other the form of screw threads t3provide m the separate cheek, to effect axial shift of the leversleeve2| and coope t With a Screw-thread engaged check as a result of theaxial shifting the pin 24 when the axis of the hub I9 is dis- 1, whereinthe lever is formed with a collar end, under e actlon 0f the screwmg oneof the separate cheeks, the lever being retralned by the Screwed Sleeve1t recelves a strained against displacement at such distant slight axialmovement resulting 1n a modificapoint, the cam means compnsmg a helicalSlot tion of the diameter of winding of one of the compensation of thetension of the belts in pro- A Variable speed contr device for usestruction above described and. shown in the y Saiii d v Comprising anon-rotative its elements, without, for this purpose, clepart- 7 ingfrom the scope of the present invention. relatively axially shiftablealong, and journaled 7 s for rotation about said hub, two connected butoppositely facing pulley cheeks disposed intermediate the spaced-apartseparate cheeks, each of the connected checks in position complementalto its respective one of the separate cheeks, said connected cheeksbeing mounted upon the hub for rotation thereabout and for shiftingaxially therealong relative to said separate checks, for expansion andcontraction of the two expandable pulleys thus constituted, meansoperatively interconnecting the several checks for conjoint rotation inall expanded or contracted positions, means to tilt the hub about saideccentric mounting means, and thus to effect displacement of the hub andits pulleys along the part-cylindrical path, belt and conversely toother, and vice versa, and so to shift the connected cheeks axially, toeffect expansion of the one pulley and consequent contraction of theother, means reacting between the hub and one of said separate cheeks toeffect axial approach or recession of the said separate cheeks relativeto one another, independently of shifting of the connected cheeks, andmeans automatically the hub to energize said sating axial shift of theseparate cheeks relative to one another, and to maintain substantiallyconstant the tensions in the two V-belts in the several tilted positionsof the hub.

4. A variable speed control device as in claim hub 3, including a leverthreadedly received on the t one of said separate cheeks, to constitutethe approach-effecting means, and means to restrain from displacementthe end of said lever which is distant from the hub, during tilting ofthe hub, to conto energize the approach-effecting means.

5. A variable speed control device as in claim 1, wherein the hubdisplacing means includes guiding means includes straight slots alsoengaging the ends of the hub and directed transversely of the length ofsaid rocking levers, to guide the hub in a definite planar path.

References Cited in the file of this patent UNITED STATES PATENTS NumberNumber Name Date Jacobsen May 9, 1939 Jacobsen May 9, 1939 JudelsohnFeb. 27, 1940 Tautz July 30, 1940 Irwin Dec. 23, 1941 Wallace July 24,1951 FOREIGN PATENTS Country Date Great Britain A. D. 1911

